Wheelchairs of the type contemplated herein, generally include a pair of drive wheels which are manually or power driven. The wheels are provided with pneumatic tires having various thread configurations to provide traction for ordinary use. These tires even though provided with special thread configurations may slip on any kind of slippery or icy surface. It is not unusual during cold weather for a wheelchair to become immobilized due to spinning of the drive wheels. The user is thereby subjected to unnecessary exposure to cold weather as a result of the inability of the wheelchair to move on such surfaces.